Process of manufacturing mixed hydrogen and nitrogen.



G. P. SUHOLL.

PROCESS OF MANUFACTURING MIXED HYDROGEN AND NITROGEN.

APPLICATION TILED 001'. 6. 1908.

1,123,394, v Patented Jan. 5,1915.

40,74 I-n uawtoz 36. flttoznu A an. 4 /m7' UNITED STATES PATENT orrron.

enonen r. SCHOLL, or NEW Yonx, N. x, nssrenen, .ro wns'rmenousn LAM]? COMPANY, conrona'rmn or PENNSYLVANIA.

PROCESS OF MANUFACTURING MIXED HYDROGEN AND NITROGEN.

Specification of Letters Patent. t nt 5, 1915',

Application filed October 6 1908. Serial No. 456,474.

To all whom it may concern: t copper turnings or other forms. of copper. Be it known that I, GEORGE P. SoHoLL, a exposing considerable surface and which citizen of the United States, and resident of are heated to a high temperature in any 'New York, county of New York, State of desirable manner. The ammonia and air 4 New York, have invented certain new and passing over the copper turnings are disuseful Improvements in Processes of Manuassociatedinto nitrogen and hydrogen and 60 featuring Mixed Hydrogen and Nitrogen, the resulting mixture of gases passes into of which the following is a specification. a condensing tank for removing the steam In certain chemical operations it is tie and then through purifying bottles containsired to use a mixture of nitrogen and hying sulfuric acid to remove any excess of drogen. Heretofore it has been customary ammonia. It may then be passed through to obtain hydrogen and nitrogen separately a solution of ferrous-sulfate which acts as and to thenmix them. Thus, for instance, an indicator and turns black or very dark it has been the practice to obtain the hydrowhen the remnant of oxygen is unduly gen by electrolytic action upon .water and large, although this latter precaution is not to obtain nitrogen by the decomposition of necessary when accurate portlons of air and air by passing the air over heated copper ammonia .are observed. tubes in the presence of more or less am- The accompanying drawing shows a conmonia. venient arrangement of apparatus for car- My invention aims to producea mixture rying out my invention.

Referring to the drawing, 1 represents a ofnitrogen and hydrogen bya single operation, and this is accomplished by employing lead-lined storage and mixing tank for reammonia as the source of both the nitrogen ceiving the mixture of ammonia and air;

. for the required purposes. Ammonia alone heating the generator.

' .of nitrogen.

apredetermined pressure, say, fine ounds and. air passing over the copper turnings ismhowmbpthenre their.iixitro'dueedsintow iron pipesacontaining :erer jvpurp s d and hydrogen and adding only sufiicient air 2 is the ammonia generator which is shown to make-the hydrogen percentage low enough as being surrounded by a steam pipe, 3, for The generator is supplied with an inlet, 4:, for supplying the liquid ammonia, and with a gage, 5, for In the treatment of tungsten compounds indicating the amount of liquid ammonia. in for the purpose of obtaining. tungsten for the generator. A siphon, 6, is provided for the manufacture of incandescent electric drawing ofi" the ammonia when desired, and s5 lamps, it is found desirable to have a mixa thermometer, 7, is provided for indicatture of nitrogen and hydrogen much less, ing the temperatures; likewise, a pressurerich in hydrogen and richer in nitrogen gage, 8, for indicating the pressure. A pipe, than the Iabove. Usually about 50% of 9, leads to the storage tank 1, and the preswill yield about 15% of hydrogen and 25% hydrogen and 50% of nitrogen makes a very sure-of ammonia-gas admitted into the tank .efiective mixture. Therefore,

enough air is is indicated by the gagelO. The air is adadded -to the ammonia to bring about the mitted into the storage tank through a pipe, proper proportions. -11, under pressure, in any convenient man- The process of operation consists'in'using ner. A pipe, 12, leads the mixedammoniaa closed vessel in which ammonia 'is vagas and air from the tank toiron pipes 13, porized by steam pipes, or in some other containing masses of copper turnings. convenient vmanner until a pressure of These pipes are heated by burners, 14, suptwenty or thirty pounds is obtained in the plied with air and gas in the proper provessel. This is drawn into a reservoir until portions. The constituents of the ammonia v To t s are-disassociatedand hydrogen and nitrogen there is admitted the requisite amount 0 amrtdiragn oif through the pipe 15, and under pressure until the pressure gage of passe I ougha conenseeeeikifi, which the reservoir indicates a, predetermined extracts tl%& water formed by the chemical pressure, say, ten pounds, although there reactions. e 'vrnay;beawithoutmaterial detriment, a slight nitrogen is th passed through wash bot- -;;excess'..of the; ammonia. This. mixture is vtles, 17, and is t e readyfor use for whatsi fued. Aspecial to mixture of hydrogen and which it is peculiarly applicable is the preparation of tungsten filaments for incandescent electric lamps.

While, what may be termed a correct chemical equation, cannot be given for the reaction which occurs when the mixed gases pass over heated copper, the following equation indicates the said reaction approximately:

In actual practice, six cubic feet'of ammonia are mixed with five cubic feet of air, and fourteen cubic feet of mixed gases are obtained therefrom, containing approximately 50% of hydrogen and 50% of nitrogen. The heated copper apparently does not take an active part. in the reaction, but serves merely as a sort of catalyzer, and in ,all probability is oxidized and reduced continually. For the best results, the copper should be heated to approximately 720 centig-rade, though good results may be obtained at other temperatures.

My process is capable of application over a wide range of gas mixtures. lhe upper limit of the amount of air that may be mixed with the ammonia is represented by the equation In this mixture the hydrogen of the ammonia is just sufiicient to take up the oxygen of the air and the addition of more air would result in the presence of free oxygen in the final product, with disastrous results.

From the amount indicated in the above equation, the proportion of air in the initial mixture may be reduced to an infinitesimal amount, the proportions of nitrogen to hydrogen in the final product approaching.

three to one as .a limit, as indicated, for ex ample, by the following reaction:

My invention is not limited to any specific ratios of gases but I may employ any mixtures between the above indicated limits.

Since, at constant temperature, the volume of a gas is inversely proportional to the absolute pressure (Boyles law) it follows that, having derived X from the above equation, the relation between the absolute pressures of the ammonia gas and the ammonia air mixture may be ascertained. Letting P represent the absolute pressure of the ammonia, of any desired convenient value, the absolute pressure of the ammonia air mixture is greater than P in the ratio der a given pressure, adding air under pr ssure until the mixture reaches a pred mined pressure, and dissociating the monia of the mixture.

2. The method of obtaining a mixture of nitrogen and hydrogen wherein the ratio of nitrogen to hydrogen has a value R which comprises mixing ammonia gas and air in a ratio X, where X equals substantially dissociating the ammonia of the mixture and combining the oxygen of the air with hydrogen.

3. The method of obtaining a mixture of nitrogen and hydrogen wherein the ratio of nitrogen to hydrogen has a value R which comprises mixing ammonia gas and air in a ratio X, where X equals substantially charging a closed container with ammonia gas, ascertainlng the absolute pressure thereof, introducing air until the absolute pressurewithin the mntainer is approxi-v mately four times the absolute pressure of V day of September, A. 1).1908.

the ammonia, and passing the gas mixture over a catalytic 7 agent, whereby the am- 5 monia is dissociated and the-oxygen of the air caused to combine with hydrogen. 7

Signed at New York,inthe county of New GEORGE P.- so oLL;

.Witnesses:

" WM. H. CArEL,

THos. H. BROWN.

It is hereby certified that in Letters Patent No. 1,123,394, gran ted January 5,. 1915, upon the application of George P. Scholl, of New. York N Y., for an improvement in Processes of Manufacturing Mir ed Hydrogen and Nitrogen, an

error appears in the printed specification requiring correction as follows: Page fz,

line 45, for the symbol H read 137 0, and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 26th day of January, A. D., 1915 [SEAL] I R. F. WHITEHEAD,

Acting Commissioner of Patents.

York, and State of NeWaYork, this 28th 

